From Farshid Lashkari, "As discussed, I've added the ability to handle Drawable objects within the NodeVisitor class. Here is an overview of the changes:

- Added apply(Drawable) and apply(Geometry) to NodeVisitor

- Added accept(NodeVisitor) method to Drawable/Geometry

- Added traverse(NodeVisitor) to Geode which calls accept(NodeVisitor) on all Drawables

- Updated CullVisitor to use new apply(Drawable) to handle drawables. The apply(Billboard) method still manually handles the drawables since it is depends on the billboard settings. I needed to disable the traverse within billboard to prevent duplicate traversal of drawables.

- Update other osgUtil node visitors (GLObjectsVisitor, IncrementalCompileOperation, ..) to use new apply(Drawable) method.
"

include/osg/Geode

@@ -41,6 +41,8 @@ class OSG_EXPORT Geode : public Node
         virtual Geode* asGeode() { return this; }
         virtual const Geode* asGeode() const { return this; }
 
+        virtual void traverse(NodeVisitor& nv);
+
         /** Add a \c Drawable to the \c Geode.
           * If \c drawable is not \c NULL and is not contained in the \c Geode
           * then increment its reference count, add it to the drawables list and